Magnificent Desolation

On July 20, 1969, Buzz Aldrin and Neil Armstrong became the first humans to set foot on the moon. Four days later, completing a journey of more than 800,000 miles, Aldrin, Armstrong, and Michael Collins splashed down in the Pacific. The world was different afterward, and so were the lives of the three men.

In a new memoir written with Ken Abraham, “Magnificent Desolation: The Long Journey Home From the Moon,’’ Aldrin, 79, discusses the moon landing and subsequent events. The thrust of the book is about his struggles with depression, as well as alcoholism and recovery. He’ll talk about those topics tonight at McLean Hospital’s annual dinner at Boston’s InterContinental Hotel, six days before the 40th anniversary of his moon walk.

The book’s title comes from a phrase Aldrin uttered while on the moon’s surface 40 years ago. First he had used the word “beautiful’’ to describe the moonscape, he explained in a phone interview. “Then I felt that’s not really right,’’ he said. “It’s magnificent, that we’re here, that humankind has culminated in being able to do this. But there isn’t a place on Earth that is more desolate than what we were looking at. No life whatsoever. There wasn’t any way to simulate the mono-color of the moon, and the black sky.’’

Aldrin earned a doctorate from MIT in 1963. Last month he performed, as a narrator, with the Boston Pops. Tonight he’ll receive the McLean Award, given “to honor individuals who have made great strides in raising awareness of psychiatric illness.’’

What advice might he have for others who are struggling with alcoholism or depression? “Well, I’ve elected to do that more by role model than by trying to have generalities of behavior, because my case is kind of unusual,’’ he said with a chuckle.

“The number one thing that you have to do is to recognize a problem, and that’s something that you have to do, and people on the outside can try and help you, and you build up defenses against that, and that’s called denial,’’ he added. “That’s why the first step is admit it to yourself that you needed help somewhere else.’’

But it’s hard to talk with Aldrin without wanting to know more about that seminal event four decades ago, when he saw the Earth from the moon. “